This invention relates primarily to oilfield pipelines, although it is not limited to this particular field. Most oilfield pipelines employ tubular members constructed of steel and are known as seamless pressure tubing, line pipe, or standard tubing. There are many different ways in which the tubular members are joined to one another to effect a continuous fluid conducting pipeline of limitless length.
it is common to join tubular members by threadedly connecting the ends together by employment of tapered threaded connections which rely upon friction for a sealed fit. Repeated expansion and contraction of the pipeline has a deleterious effect upon this method of construction and ultimately causes the threads to stretch until leakage occurs at the threaded connections.
For this reason, there is another widely used method of connecting tubular members together by the joining of two beveled opposed ends of pipe joints in a butt welded manner. However, the cost of labor and equipment required for this method is enormous.
Still others have proposed joining lengths of steel tubular goods together by a number of different means, including the employment of grooved ends having gaskets and bolted couplers; the use of crimping tools; the application of interlocking tabs; as well as the use of o-rings and compression rings.
For example, Veitch, U.S. Pat. No. 2,498,831 connects plastic pipe together with a coupling member, and uses an adhesive as a sealing means between the marginal pipe end and the coupling member.
Reesor, U.S. Pat. No. 3,343,252 joins conduit together by employment of a knurling process with an interlocking crimping process.
Curtin, U.S. Pat. No. 3,971,574 teaches that plastic pipe may be joined with a smooth fitted coupler, and includes an outside locking coupler.
Kyle et al U.S. Pat. Nos. 1,919,734; Carter 4,014,568, Bartholomew 3,997,195; Streit 4,002,358; Lowe 4,026,584; Asano 4,043,574; Martinez 4,076,285; Ramm 3,633,943; McGuire 3,701,548; Bingham 3,807,776; Frey 4,067,534; Wise 3,843,169; Garrett 3,565,468; and Singer 2,967,067 are other examples of the multitude of approaches to the problem of forming a continuous fluid conveying conduit from a plurality of pipe joints.
The present invention constitutes a step forward over the above prior art by providing a fast, reliable, and inexpensive method and apparatus by which tubular goods are connected together into a continuous fluid conveying pipeline. SUMMARY OF THE INVENTION
This invention relates to pipeline construction, and specifically to a method of joining pipe joints to a pipe connector or sleeve to provide a new and unusual pipeline. A pair of pipe joints are arranged in spaced relationship respective to one another. The sleeve which joins the marginal ends of the adjacent pipe joints has a pipe receiving socket formed in the opposed marginal ends thereof.
Each socket of the sleeve is divided into a smooth pipe receiving portion and a grooved pipe receiving portion. The adjacent marginal ends of the pipe joints are forced through the smooth and grooved portions of the sockets, and towards one another, as the grooves deform the metal on the outer peripheral wall surface of the marginal ends of the pipe joints, thereby providing a strong mechanical connection.
In the preferred embodiment of the invention, the grooves are located externally of the smooth bore, and the smooth bore receives the marginal terminal end of a pipe joint with a friction fit. A sealant, such as epoxy resin, for example, is applied to the interface between the marginal end of the pipe joint and the interior wall surface which forms the socket. As the adjacent pipe ends are forced into the sockets of a sleeve, the pipe is twisted respective to the sleeve, or rotated about the longitudinal axial centerline thereof, thereby more evenly distributing the sealant and more firmly setting the grooves of the sleeve into the outer surface of the pipe joint.
Accordingly, a primary object of the present invention is the provision of a method by which pipe joints are joined together in the field by axially moving a pair of pipe joints towards one another and into a sleeve which frictionally engages the marginal ends of the pipe joints.
Another object of the present invention is the provision of a method of connecting adjacent ends of a pipe joint by frictionally engaging the marginal ends of the pipe within a sleeve.
A further object of this invention is the provision of a method and apparatus by which pipe joints are joined together by forcing the marginal ends thereof into a sleeve, where a sealant and high friction forces hold the pipe joints within the sleeve.
A still further object of this invention is the provision of a method of connecting the marginal ends of pipe joints together by forming a socket on one marginal end of a pipe joint and forcing another pipe end into the socket so that the pipe joints are held together by friction.
These and various other objects and advantages of the invention will become readily apparent to those skilled in the art upon reading the following detailed description and claims and by referring to the accompanying drawings.
The above objects are attained in accordance with the present invention by the provision of a method for use with apparatus fabricated in a manner substantially as described in the above abstract and summary.